1. Technical Field
The present invention relates to a sample plate for X-ray analysis and an X-ray fluorescent analyzer that are used for measurement of a sample such as a standard material in performing a fluorescent X-ray analysis in which toxic substances can be detected and which is used for screening products and the like.
2. Description of the Related Art
In a fluorescent X-ray analysis, a sample is irradiated with X-rays emitted from an X-ray tube, fluorescent X-rays emitted from the sample are detected by an X-ray detector, and a qualitative analysis of a composition of the sample or a quantitative analysis of a concentration, a film thickness, or the like is performed based on a relationship between intensities of the X-rays. Since samples can be rapidly analyzed in a non-destructive manner by the fluorescent X-ray analysis, the fluorescent X-ray analysis is widely used in the fields of process control, quality control, and the like. In recent years, high precision and high sensitivity of the fluorescent X-ray analysis are achieved, and thus trace measurement is enabled. In particular, the fluorescent X-ray analysis is expected to be spread as an analysis method of detecting toxic substances contained in materials, complex electronic parts, or the like.
Generally, when a quantitative elemental analysis is performed using an X-ray fluorescent analyzer, a standard material is measured plural times, and a relation between intensities of fluorescent X-rays and concentrations of elements needs to be calibrated based on a calibration curve (for example, see JP-A-2008-008856). Since the intensity from even the same standard material varies with an aging variation of the apparatus, the standard material needs to be periodically re-measured, and the calibration curve needs to be updated such that a quantitatively-measured concentration of an unknown sample is not changed.
The above-described technique in the related art has the following problems.
A user periodically performs a task of measuring plural standard materials in order to update the calibration curve as described above. This task has problems in that it may become highly cumbersome to a user and an error of misidentifying the samples may easily be made when there are a large number of standard materials. In addition, since unevenness in concentration value occurs in manufacturing a standard material, a target concentration cannot be completely realized. For example, even when a standard material is manufactured with a target concentration of 100 ppm, the standard material may have a concentration of 101 ppm or 99 ppm. In manufacturing the standard material, the standard material is labeled with the actually-measured value. However, in order to configure a calibration curve on software of the apparatus, the user may have to manually input the uneven concentration as a result. Depending on standard materials, there is a case in which the same standard material is used for plural calibration curves. In this case, if the same value is not input two or more times, all the calibration curves may not be updated. Since the standard materials to be measured in updating the calibration curves are almost uniform, the task may become tedious to the user. Even if there is an input error, the apparatus may have no means for automatically detecting the error in situ, and thus a calibration curve allowing wrong analysis values to be output may be created and used. Therefore, a method of reducing an operator's load and reducing an error is desired.